Geographic Range

Indonesian mountain weasels are only found on the islands of Java and Sumatra in Indonesia. Indonesian mountain weasels are island endemic and native to the Oriental biogeographic ragion. More surveys need to be conducted in these areas to determine their exact distribution and home ranges. (Duckworth, et al., 2008)

Habitat

Indonesian mountain weasels, as their names suggests, live in the tropical rainforest mountainous regions of Indonesia. However, very little is known about their preferred habitat conditions besides their preference for higher elevations. It is believed that their elevation ranges from 1,000 m to 2,200 m, but little is known of how they function at extreme elevations or if they can live outside of their range. According to the IUCN there are only 15 known specimen of the Indonesian mountain weasel, and of those only 12 have a locality. More surveys and research is needed to determine habitat range and preference. (Duckworth, et al., 2008)

Physical Description

The Indonesian mountain weasel as a weasel has very specific traits that all in their genus share. Weasels have long, slender bodies with short legs. This body design allows them to enter any place in which they can stick their heads. A long slender body has costs; while their metabolic rate tends to be similar to other mammals of the same size, they tend to lose heat much faster due to their shape (Brown and Lasiewski, 1972). The Indonesian mountain weasel tends to be between 279 m and 321 m from head to the base of the tail. The tail is about 136 mm to 170 mm long (Eaton, 2009).
There is very little information specifically on the Indonesian mountain weasel, however, we know that they have reddish-brown fur and a foramen on their skull by which they can be identified. This foramen is located "in the medial part of the auditory bullae, mid-way along the anterior-posterior axis, at the point where the bullae attach to the skull" (Meiri, Duckworth, and Meijarrd, 2007). (Eaton, 2009; Meiri, et al., 2007; Walker, et al., 1964)

Reproduction

As a member of the badgers, otters, and weasels family, Indonesian Mountain weasels have a polygnous mating system in which the males will fight for access to a female. It is noted that these fights can be extremely vicious. Weasels are solitary creatures and the mating season is often the only time adults will interact with one another. This type of behavior is called a solitary-territorial mating system (Bright, 2000). The specifics of Indonesian mountain weasel mating habits are unknown. (Bright, 2000; Moors, 1980)

Indonesian mountain weasels become sexually mature at about a year of age. Their breeding season is believed to be between March and May, followed by a gestation period of approximately 30 days. ndonesian mountain weasels, like other weasels, give birth to altricial young. This means that the young are born with their eyes shut and with very little fur. The pups rely solely on their mother for care. It takes about a month for pups eyes to fully open, and another month after which they will become fully weaned. ("Indonesian Mountain Weasel", 2004)

For weasels, care of young fall on the mother alone. Even though the young are altricial, they are fully weaned after 2 months and leave their mother. However, the litter tends to prefer to remain together until Autumn. ("Indonesian Mountain Weasel", 2004)

Lifespan/Longevity

Little is known about how long Indonesian mountain weasels live, but some suggest between 7 to 10 years of age (indonesianfauna.com, 2004). Nor do they known about the lifespan of Indonesian mountain weasels in captivity. However, other species of weasels live up to 20 years in the wild and do very well in captivity (Walker et al., 1964). (Walker, et al., 1964; "Indonesian Mountain Weasel", 2004)

Typical lifespanStatus: wild

7 to 10 years

Behavior

Very little is known about the behavior of the Indonesian mountain weasel. Other weasels tend to be solitary and nocturnal only interacting for breeding or over territory disputes. (Walker, et al., 1964)

Home Range

Since they have a solitary-territorial mating system, a females main concern is defending a home range that will provide sufficient resources for her offspring. Whereas males want to have a home range that will contain as many females as possible. However, the exact range for them is unknown. (Johnson, et al., 2000)

Communication and Perception

As with other weasel species Indonesian mountain weasels will communicate primarily with odors and secondarily with "clicks" or other auditory noises. (Erlinge and Sandell, 1988)

Food Habits

Weasels are completely carnivorous and the Indianian mountain weasel is no different. They are especially adapted to eating rodents; their agility and speed allows them to take down prey much larger than themselves. They are also very good at removing rodents from their burrows. Some species of weasels are known to stay at one prey den until they have completely eliminated all of the inhabitants. (Walker, et al., 1964)

Predation

Indonesian mountain weasels have no known predators, aside from humans. It is believed that due to their fierce nature, it would not be worth a predators effort to attempt to consume them. It is believed that some weasel species are eaten by foxes. While there are no foxes in Indonesia it is possible some of the other carnivores might be a threat to Indonesian mountain weasels. (Bright, 2000)

Ecosystem Roles

Weasels are pest controlers and have been known to eradicate species from their home ranges. (Moors, 1980)

Economic Importance for Humans: Positive

Indonesian mountain weasels are known to keep rodent populations in check; a common pest for humans. (Walker, et al., 1964)

Positive Impacts

controls pest population

Economic Importance for Humans: Negative

No specific negative effects to humans are known, but weasels are known to eat poultry. This can be a big problem for farmers in the area who use poultry as a main source of income or food. (Walker, et al., 1964)

Negative Impacts

household pest

Conservation Status

Indonesian mountain weasels are endangered because they are endemic to a very small area and because they are very poorly known. They are among the rarest of the weasel family and face issues with habitat fragmentation. Habitat fragmentation has a very strong correlation with declines in weasel abundance. (Bright, 2000)

Contributors

Glossary

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

fossorial

Referring to a burrowing life-style or behavior, specialized for digging or burrowing.

island endemic

animals that live only on an island or set of islands.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

polygynous

having more than one female as a mate at one time

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

tactile

uses touch to communicate

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

Disclaimer:
The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

This material is based upon work supported by the
National Science Foundation
Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.